Boston's NPR news station, WBUR, reached out to dozens of Warren's former students from Harvard University, but none of those they spoke with had negative things to say about her.

She was popular at Harvard, and one former student said that as a law professor, Warren strove to "make sure you understand every single thing about the case" rather than just understanding legal doctrine or rules, the station reported.

Brown and Warren both made live appearances at the Red Sox home Friday for Fenway Park's 100th anniversary, The Boston Globe reported.

Warren addressed concerns she's heard about how families are struggling with college costs, and Brown touted his bipartisan record, according to the Globe, which paraphrased Brown as saying Massachusetts voters "need someone in the otherwise all-Democratic delegation who can communicate with the Republican-controlled House of Representatives."

To read more of the Globe's piece on Brown and Warren's appearances at Fenway, click here.